Cardas ultra pure, tin/lead/silver/copper, quad eutectic .032 solder. The rosin core is what most of us are familiar with and this can be used anywhere. The .032" diameter solder does not leave large amounts of rosin residue on your project like the Kester "44". 10 gram pack is approx. 9ft. in length. This solder is very easy to work with. We also sell 10g packs of WBT.